1. Field of the Invention
The present invention relates to an electric connector for use in a vehicle such as an automobile and the like and, in particular, to an electric connector which is used to secure double connecting terminals respectively inserted into a connector housing not only by securing lances but also by retainers in such a manner that the secured condition of the connecting terminals by the retainers can be detected easily and positively.
2. Description of the Related Art
As an example of a conventional electric connector of the above type that the connecting terminals inserted into the connector housing are secured double not only by the securing lances but also by the retainers, there is known an electric connector having such a structure as shown in FIG. 1. Referring now to the conventional structure shown in FIG. 1, reference character 1 designates a connector housing. In particular, in the connector housing 1, there are formed a plurality of terminal storage chambers 2 which extend substantially parallel to one another and, in the terminal storage chambers 2, there are provided their associated securing lances 3 in such a manner that the securing lances 3 are formed integrally with the connector housing 1. Also, on the outside portion of the connector housing 1, there are disposed two or more retainers 5 which are connected and held by their associated bands 4 provided from the outside portion of the connector housing 1. These retainers 5, as shown in FIG. 1, are held in their respective preset conditions within their associated retainer insertion holes 6 respectively formed in the wall surfaces of the connector housing 1, in order to prevent the possibility that, when the connector housing 1 is delivered (transported), the retainers 5 can swing loosely or can be cut off from the bands 4. Also, the connector housing 1 is structured such that, after connecting terminals 8 are completely inserted into their respective terminal storage chambers 2, if the preset retainers 5 are inserted into their respective terminal storage chambers 2 deeper than the above-mentioned retainer insertion holes 6, then the insertion front end portions 7 of the retainers 5 are inserted into their respective terminal storage chambers 2 of the connector housing 1 and are thereby secured to the connecting terminals 8.
In particular, the connecting terminals 8 inserted into their respective terminal storage chambers 2 of the connector housing 1 are prevented against removal not only by the securing lances 3 that are disposed within their respective terminal storage chambers 2 of the connector housing 1 but also by the retainers 5 that are inserted into their respective terminal storage chambers 2 through the retainer insertion holes 6. That is, the connecting terminals 8 are prevented by such double securing means from removing from their respective terminal storage chambers 2.
After the insertion operation to insert the connecting terminals 8 into their respective terminal storage chambers 2 is completed, a check connector 10, which has been prepared previously, is fitted with the connector housing 1 to conduct a test as to whether the connecting terminals 8 and wire harnesses 9 connected to their respective connecting terminals 8 are connected together correctly at their proper positions or not. If the test shows that they are connected together correctly at their proper positions, then the connector housing 1 can be delivered to the following step.
As described above, in the above-mentioned electric connector structure, when the retainers 5 are held in their preset conditions (in half fitted conditions), the connecting terminals 8 are respectively inserted into their associated terminal chambers 2 and are thereby secured to their associated securing lances 3. Next, as a second insertion operation, the preset retainers 5 are further inserted into their associated terminal chambers 2 still deeper and the insertion front end portions 7 of the retainers 5 are thereby secured to their associated connecting terminals 8, so that the connecting terminals 8 are secured double by the retainers 5 and securing lances 3. However, for example, assuming a case in which the above-mentioned second insertion operation of the retainers 5 is forgotten, the connecting terminals 8 are prevented against removal only by the securing forces of the securing lances 3 within the terminal storage chambers; that is, the connecting terminals 8 are not secured double but they are held in a connected condition (namely, the condition shown in FIG. 1) in which their securing forces are short.
In spite of the above short securing force condition, if the check connector 10 is fitted with the above connector housing 1, then the check connector 10, as shown in FIG. 2, is able to advance while moving back the retainers 5 by the front end edge thereof and can be completely fitted with the connector housing 1; that is, due to the complete fitting of the check connector 10 with the connector housing 1, connecting terminals 11 provided within the check connector 10 can be connected normally with the connecting terminals 8 singly secured only by the securing lances 3. Therefore, as the result of the connection check, no abnormal condition can be found. In other words, there is a possibility that such singly secured electric connector can be shipped or delivered to the following step as a normal electric connector while the connecting terminals 8 thereof are held in a singly secured condition only by their associated securing lances, that is, the connecting terminals 8 are not secured double by the retainers and securing lances.
Also, as another conventional electric connector, there has been known an electric connector disclosed in Japanese Patent Unexamined Publication No. Hei 5-226025. According to this publication, the electric connector is formed of synthetic resin by injection molding or by similar means and, as shown in FIGS. 3 to 5 a housing 110 and a retainer 120 are formed integrally with each other through a band hinge 130. In the interior portion of the housing 110, there is formed a terminal storage chamber 140; and, in the terminal storage chamber 140, there is provided a flexible securing piece 141 which is used to secure a terminal metal member 150 and also there is formed an opening 142 through which the retainer 120 can be inserted.
In the retainer 120, there are provided a terminal securing projection 121 and a fully securing projection 122, whereas in the terminal securing projection 121, there is provided a provisionally securing projection 123. Before the terminal metal members 150 are inserted, when the electric connectors are moved while they are piled up on top of another in such a manner that the retainers 120 are separated from their respective housings 110 by the band hinges 130, there is a possibility that the electric connectors can be entwined together. In order to avoid such possibility, the electric connectors are moved while they are collected together in such a provisionally connected condition as shown in FIG. 4 in which the retainers 120 are respectively inserted into their associated openings 142 and the provisionally securing projections 123 are respectively secured to the peripheral edges of their associated openings 142 due to the elasticity of the band hinges 130. The provisionally securing projection 123, as shown in FIG. 3, includes two tapered surfaces 123a respectively formed in the inserting and removing directions thereof, so that the projection 123 portion of the retainer 120 formed slightly larger than the width of the opening 142 can be made to pass through the opening 142 easily.
To complete the assembly of the provisionally connected electric connector, the terminal metal member 150 may be inserted into the terminal storage chamber 140 to be thereby secured to the flexible securing piece 141 and, next, the retainer 120 may be pushed into the terminal storage chamber 140 so that the terminal securing projection 121 can press against the terminal metal member 150 and the fully securing projection 122 can be secured to the peripheral edge of the opening 142.
However, in the above-mentioned conventional electric connector, because the retainer 120 or the provisionally securing projection 123 thereof is simply secured to the peripheral edge of the opening due to the elasticity of the band hinge 130, there is a case where, in the connectors collecting and moving process, the retainer 120 is pushed further into the terminal storage chamber 140 beyond the provisionally connected condition, and as shown in FIG. 5, the terminal securing projection 121 of the retainer 120 is secured to the peripheral edge of the opening 142 to thereby leave the retainer 120 in an obliquely inserted manner. Due to this, when inserting the terminal metal member 150, the terminal metal member 150 cannot be inserted up to a given position where it can be secured to the flexible securing piece 141. This gives rise to the poor assembly of the terminal metal member 150 and also the number of assembling man-hour increases for correction of the poor assembly.